About UPC and EAN codes

What are these codes?
The Universal Product Code (UPC) is a barcode symbology that is
widely used in North American and in other countries for
tracking trade items in stores. It consists of a set
of digits that identify the producer and the product.

The European Article number ("EAN") was developed
as a superset of the UPC where an extra digit is added to the
beginning of every number, expanding the number of codes from
100 million to 10 trillion codes. The EAN codes indicate
the country in which the company that sells the item is based.

The code appears as a block of thick and thin vertical lines
alternating in dark and light colors above a sequence of 12 (UPC)
or 13 (EAN) numbers.

What information is in the code?
The codes are typically visually divided into three parts. The left-most
portion will be a string of 5 or 6 digits. This is followed by a strng
of 5 digits and a single number to the right.

Sometimes, as in the example, there will be a separate number to the left that
indicates the country in which the owner of the trade item is
located. Since this is 0 in the US, it is often omitted on US products.
The next six digits identify who the "owner: of the
item is. In both cases, the next 5 digits
comprse the number the owner uses to identify the product. The
right-most digit is a check digit used in the scanning process
to ensure the label was correctly read and decoded by the
scanner.In the example above:

4 is a check digit that is calculated from the prior numbers and that is used by scanners
to ensure that the number was correctly captured.

Note that in both UPC and EAN codes, the first digit may indicate that the
code is a special purpose code.

There are some compressed versions of UPC codes (5 and 8
digits) that are usually expanded to 12-digit format before
being used. For purposes of this discussion, consider these to
be the same as the 12-digit codes.

Every item that a company sells, as well as every size
package and every version of packaging has a different item
code. Thus, the code will tell you whether the item
that the code identifies is a 8-ounce can of soda or the same
soda in a 2-liter bottle.

Click here for an excellent website that discusses
bar codes in general and UPC/EAN codes in particular.

What can I learn from a UPC / EAN code?
If you scan the code with Digit-Eyes and we find it in the
database, at a minimum, you can learn the name of the
product. If the manufacturer has made information
available about how to use the product, its ingredients or its
nutritional value, that is also available. Digit-Eyes will
also provide a link to our original source of the information
plus additional links that you can use to search for more
information about the item.

Are all UPC / EAN
codes unique?
No. Most UPC and EAN codes are unique and indicate the branding
of an item. However, there are some special classes of codes
that have different meanings. These are not unique:

UPC codes that start with the number 5 and EAN codes that
start with "05" or that have a beginning value
between 990 and 999 are coupons. It is common, but by no
means guaranteed that substituting a "0" for the
"5" and dropping and recalculating the check digit
will give you the identification of the item
to which the coupon applies.

Codes that have a starting value between 981 and 982 are
common currency coupons.

UPC and EAN codes that start with the number 2 or "02" and EAN
codes that start with "002" are random weight
items. In this case, the code is unique only to the store.
Typically the left portion of the code is used to indicate
the product to the store's point-of-sale system and the
right portion and is used to indicate the weight of the
item. This allows the POS system to calculate the price of
the item without re-weighing it at checkout time.

UPC codes starting with the number 4 and EAN codes
starting with "04" are locally priced items where
the meaning of the code is unique to the store. Generally,
these use the left part of the code to denote the local item
number to the store's POS system and use the right part to
indicate the price or weight of the item, depending on local usage.

Will the UPC or EAN code indicate the country where the
product was made?
Possibly, but not necessarily. The left portion of the code indicates the country in which the company that
has trade responsibility for the item is based. Thus, if a
British company sells crisps that were made in Poland and
labeled to the British company's specifications, the left portion of the
code will indicate Britain, not Poland. This is because the British
company has the trade responsibility for the item. In the case
where the British company is buying and redistributing a product
that has a brand on it that is not their own, the code will
generally indicate the country where the owner of the brand is
located. Click here
to read more on this topic.

Is there a database of UPC and EAN codes that I can
get? There is no central database of UPC / EAN codes.
The Digit-Eyes database is proprietary and is created by our software. The Digit-Eyes database
is available to other companies through our API (Applications Program Interface).

Does Digit-Eyes have all the UPC / EAN codes?
No way. But we do have quite a lot of them! 43,648,756
codes as of midnight last night, to be exact.

What happens if a code I scan with Digit-Eyes is not found in the database?

You are given a chance to enter the name of the product if
you know it. This is immediately added to the
database and becomes available to everyone. It is then
checked by our staff and the number is added to a special high-priority queue for processing.

the practical effect is that it is fairly common that find
within 24 hours or so that the code that was previously not
found is now in the database.

What if I find that the description associated with a
code is wrong?
Click the link titled "report wrong description" and
it will be flagged for immediate review.

Are there other kinds of barcodes?
Yes, there are many types. UPC and EAN codes consist only
of numbers and are only used for product
identification. Other bar codes like Code 3-of-9 and
code 128 have letters as well. These are used for
many purposes. Inventory control is a common
one. The full version of Digit-Eyes will read code 3-of-9
and code 128.

Can UPC and other codes be applied other than with a
printing press? I saw a barcode tattoo and it looked
pretty cool.All are decoded by measuring the distance from leading
edges to leading edge of bars, trailing edge to trailing edge of
bars and leading edge to leading edge of characters and the
tolerances are fairly exacting. It is very difficult to
achieve this except with a printing press.

Thus, if you're thinking of getting a tattoo of a barcode, don't
expect it to be readable with a scanner unless it is extremely large. Even when the
tattoo is new, the tolerances for reflectivity and spacing are
very unlikely to be met with ink embedded in skin and, as the
tattoo stretches with time, this will become even less
true. Really determined? You can buy a set of custom, scannable temporary
tattoos here

Just for funClick here for an interesting website that
features barcode art.